Process of forming and binding material for use in abrasive wheels and the like.



PROCESS OF FONG AND BINDING MATE I i as r JAMES G. VAIL, OF CHESTER, AND JOHN D. CARTER, 0F LANSDOWNE, PENNSYLV I non use in annaslvn a AND THE LIKE.

No Drawing.

To all whom it may concern:

Be it known that we, JAMES G. Van. and Jon): D. CARTER, citizens of the United States, and residents of Chester, county of Delaware, and State of Pennsylvania, and of Lansdowne, county of Delaware, and State of Pennsylvania, respectively, whose post-ofiice addresses are the same, have invented a certain new and useful Process of Forming and Binding Material for Use in Abrasive Wheels and the like, of which the following is a specification.

Various attempts have been made in the past to utilize alkaline solutions of the various silicates, notably silicates of potassium and of sodium, as a binding material in forming abrasive wheels and similar ars ticles, it having been found that wheels made with such binding materials are especially adapted for certain classes of work. However, while it has been possible to pro duce a satisfactory wheel with a binding material of this nature when the abrasive material employed was emery, and possibly certain other materials, it has hithertobeen impossible to produce a commercially satis factory article when carborundum is made use of as the abradant.

The principal objects of our invention are to provide a process by which an abrasive wheel or similar article in which carborundum. or other substance having substantially similar chemical properties, is employed as the abradant, may be formed by the use of solutions of alkaline silicates as a binding medium, and which when finished shallpossess extreme hardness and durability. shall be eflicient in operation, and in which the component particlesof the abradant shall be so firmly bound together that the tendency to burst'when rotated at high speed shall be negligible: to provide such a process, which may be readily, cheaply and effectively .car- I ried out in factories at present engaged in the manufacture of abrasive wheels, and with the machinery now in use; to provide a binding material for use in wheels and similar articles. and in furnace linings and the like in which carhorundum, or other substance having substantially similar chemical properties. is employed. which shall serve to firmly unite the particles together, and by the employment of which new and superior results will be obtained; and to provide an Specification of Letters Patent.

abrasive wheel or the like of new and advantapeous properties.

A urther object of our invention is to provide a process of forming abrasive wheels in which carborundum or the like is employed as the abradant, which shall permit of the use of Webs within the wheels, should it be desired to employ them.

Our invention further includes all of the various other novel features and operations hereinafter more definitely s ecified.

In the manufacture of a rasive wheels and similar articles, as now carried on, in which the binding material consists of an alkaline solution of a silicate, it is customary to mix together the abradant material, a hydrous clay or similar substance which may be termed the filler, and the binding material. The mixing of these substances may be performed in any convenient order, and in any desired proportions, a quantity of the binding material, which may consist of a strongly alkaline solution of silicate of sodium or a somewhat similar silicate, being employed preferably sufiicient to reduce themixture to'a plastic mass of the desired consistency. This after being thoroughly mixed may be forced into suitable molds Patented May l8, i915.

Application filed November 4, 1913. Serial No. 799,105.

and baked at relatively moderate temperatures until the excess moisture is eliminated,

after which the finished wheel may be with drawn from the mold. If it be desired-to 1 production of whmls and similar articles in which carborundum is employed as the abradant, as the wheels made thereby possess numerous disadvantages, among which may be mentioned their softness, inferior cutting quality, and tendency to disintegrate whenin operation, thus practically prohibiting their commercial use. It has, therefore, been customary to bind the particles of carborundum together by the use of a ceramic bond, the material from which. the bond is formed being'placed in a suitable mold together with the carborundum employment of webs within a wheel formed in this manner is impossible, as the heat necessary to properly fuse the ceramic material used as a binder, also serves to melt the metallic web,thus rendering it useless.

We have found, however, that an alkaline solution of a suitable silicate may satisfactorily be employed as a binder for carborundum, or other substances having substantially similar chemical properties, by the employment of a suitable ox dizing agent during the carrying out of the process of forming the wheel or like article, and that a Wheel may thus be. produced having none of the disadvantages of the carborundum wheels employing ceramic. binders, while possessing distinct advantages of its, own. While it is possible to utilize various oxidizing agents j with good results, we have found that'in practice a suitable amount of potassium permanganate, preferably in crystal form, although this is not essential, may be satisfactorily employed, and that excel- .lent results may be obtained by the mixture of, for example, say five per cent. by weight of this substance with an alkaline solution of sodium silicate in strength of, say, 60

Baum, preferably while the latter is heated. I While the addition of the oxidizing agent may take place at any suitable time during the process of preparing the plastic mass out of which the'wheel orother article is formed, the oxidizing agent may preferably be added to the silicate solutionprevious to the addition. of the latter toothe carborundum and hydrous clay or other filling material. The proportions of the carborimdum or like substance and h drous clay, or other filling material, emp oyed may be regulated as may be desired, and after the addition of the binding material, composed.

of the silicate solution containing the potassium permanganateor other oxidizingagent, the resulting plasticemass anaynbcrtrsgted in a manner similar to that now employed'in the manufacture of silicate wheelswemploying emery or other like substance as the abradant.

It seems probable that the difliculties previously encountered when efforts were made to form an abrasive wheel in which carborundum, or other substance of substantially similar chemical properties, was employed as the abradant and an alkaline solution of a silicate as the binding material, arose from the presence of free hydrogen gas liberated by the action of the 'alkalme silicate upon the carborundum, this gas probably forming either minute bubbles within the mass or else envelopin the particles of carborun um with a sort 0 sheath or coating, and preventing the binding material from properly adhering thereto. It is thought, however, that the oxygen in the oxidizing agent which we employ, by combining with the liberated hydrogen to form water, practically eliminates the objectionable hydrogen gas, and thus permits the bindin material to exert its maximum strength. t will thus be evident that the same result may be accomplished .whether a relatively concentrated solution of an alkaline silicate be employed, or whether a less concentrated solution, to

' which has been added caustic soda or caustic potash, or similar substances, be made use of, as the oxidizing agent will, in any case, serve to combine with the gas which may be generated and which by its presence may serve to impede the action of the bindingmaterial.

Furthermore, it will be noted that our process may be employed with good results in any case where it be desired to firmly unite articles of material other than carborun um with a binder comprising a solution of an alkaline silicate, wherever the nature of the particles be such that their 7 contact with the binding material will serve to liberate uncombined gas within the mixture.

' Furthermore, if desired, webs formed of practically any material may be employed in wheels formed according to our process, as the tem eratures necessary to properly bake the w eel are not suflicient to in any way affect the web, and it is possible, therefore, by the use of our process to produce acarborundum wheel having a web formed -of material which melts at a comparativel low temperature.

we have found-it desirable to combine the 'same with the binding material previous to its mixture with the carborundum, nor do wedcsire to limitnurselves to the employment of any specificoxidizing:-agent.;;

, Furthermore, it will be evident that a suitable binding material for use in our rocess may be manufactured as alaaparate industry apart from the manufacture of the wheels or other articles themselves, and may be utilized in the production of linings for 'furnaces and for many other purposes,

as well as in the roduction 10f wheels and the like, and we esire to cover the manumemes facture of such substance, as well as the substance itself.

Finally, it will be evident that various changes may be made in our invention, as herein described, and in the various steps of our process, as well as in the method of cffectuating and carryingout the same, without departing from the spirit and scope of our invention as defined in the appended claims.

Having thus fully described our invention, we claim and desire to protect by Letters latent of the United States:

1. The process of forming an abrasive wheel or the like, which comprises the use of carborundum, an alkaline solution of a silicate and an oxidizing agent soluble therein.

2. The process of forming an abrasive wheel or the like, which comprises the use of an alkaline solution of sodium silicate, and potassium permanganate.

r'lhe process of forming an abrasive wheel or the like which consists in combining an abradant capable of yielding hydrogen gas when in contact with an alkali with a binding material comprising an alkaline solution of a silicate and an oxidizing agent soluble therein, and'then baking the resulting mass in molds suitable to produce articles of the shape desired.

4. The process of forming an abrasive wheel or the like, which consists in mixing carborundum with a suitable filler, reducing the mixture thus formed to a plastic consistency by the addition of an alkaline solution of a silicate in combination with a suitable oxidizing agent, introducing the plastic mass into suitable molds, and baking the same at a relatively low temperature.

5. The process of formin an abrasive wheel or the like which consists in mixing carborundum with a suitable filler reducing the mixture to a suitable consistency by the addition of a binding material comprising a solution of sodium silicate and potassium permanganate, introducing the resulting product into suitable molds and baking the same at relatively low temperatures.

6. As a new article of manufacture, a molded abrasive wheel or the like formed of a composition comprising a suitable 'abradant yielding hydrogen gas when in contact with an alkali, a solution of an alkaline silicate, and an oxidizing agent soluble therein.

In witness whereof We have hereunto set our hands this 3rd day of November, 1913.

JAMES G. VAllL.

TEE.

Witnesses:

Annxsnnnn PARK, Gnoncn it. Hansen. 

